A router in a communication network, upon receiving a packet, can read the packet's routing information, select a route, and then forward the packet to a next router in the route. The router has collected information about routes on the network that can be used to perform route selection when forwarding packets. When the router detects a failure of a neighboring router in a current route topology, a reconvergence of the route topology occurs, in, e.g., link-state routing protocols, for example, open shortest path first (OSPF) and intermediate system to intermediate system (IS-IS).
Reconvergence includes a process in which the router selects an alternative path to the destination networks that are affected by the failure. Reconvergence conventionally is a three step process performed by the router, which includes the following: (1) detection of the actual failure; (2) re-calculation of the route topology utilizing topology information, to obtain an alternative route to the destination in the routing information; and (3) updating the routing table in the router. Conventionally, these three steps occur in a sequential manner. Consequently, the total time of reconvergence is the sum of time for each of these steps.